Friction shock-absorbing mechanism



1921 2 Sheets-Sheet 1 Junel 23, 1925.

J, F. OCONNOR F'RICTION SHOCK ABSORBING MECHANISM -ibriginal Filed Juneso,

June 23, 1925.

J. F. ocoNNoR FRICTION SHOCK ABSORBNG MECHANISM wif Patented June 23,1925.

' UNITED-'STATES PATENTL oFFlcE.

IOIINF. ocoNNoIt, or CHICAGO,4 ILLINOIS, AssIGNo'R, BY MESNILASSIGNMENTS, To W. II. MINER, ING., Al oomfoRATIoN or DELAWARE.

*FBICTIoN SIIOGKQABSORBING MECHANISM."

Application 'led- .'luneV 30, 1321, `Seriall No. 481,555. .-'RencwedvOctober 24, 1,924.

To all whom t may concer/11.." v f- Be it known that I, JOHN F.OC'ONNOR,n a citizen of the United States, residing at Chicago, in thecounty of Cook-andi State of Illinois, have invented la certain new anduseful Improvement in` FrictionShock- Absorbing Mechanisms, of which thefollowing is a full, clear,l concise,. and exact description,reference-being had to the .accompanying drawings, forming a part ofthis specication.

This invention relates to improvements in l friction shock absorbingmechanisms.

One object of the invention is to provide a high capacity frictionVshock absorbing mechanism especially adapted for railway draft riggingsand wherein is obtained cery tain release.

A more specific object of the invention is to provide a mechanism of thecharacter indicated having a preliminaryV spring of unusually highcapacity so arranged that said spring is actuated underminor shockstransmitted to the mechanism without any appreciable actuation of Vtheyfriction elements or main Spring resistance, thereby prolonging thelife of the mechanism.

Other specifick objects of the invention are to provide a mechanism ofthe character indicated wherein are employed relatively blunt andrelatively keen wedge faces, the parts being so arranged that the actionchanges automatically .from a blunt wedge condition to a keen wedgecondition during a compression stroke and also to provide a wedgearrangement possessing both blunt and keen wedge-acting faces, of aself-releasing character.V t

Other objects of the invention will more clearly appear from thedescription and Yclaims hereinafter following.`

In the drawings forming a part of this specication, Figure 1 is ahorizontal longitpdinal sectional view of a portion of a railway draftrigging vshowing my improvements in connection therewith, the conditionof the shock absorbing mechanism being that which obtains under fullrelease or normal position. Fig. 2 is a vertical transverse sectionalview corresponding substanof friction shoes C .y and wedge D; a separatewedge element E a tially to the line 2-2 of Fig. 1. Fig. 3 is averticallongitudinalcentral sectional View of the shock absorbingmechanism proper, shown in Fig. 1. Fig. 4 is a view similar to F ig.1but-illustrating thevposition assumed vby the'parts just as the keenangled wedges come intoengagement with the correspondingwedge faces ofthe friction shoes. And Figures 5, 6 and 7 are detail perspectives ofthefollower wedge member, blunt wedge member and one of the friction shoes,respectively. j

In said drawings 10`-10 denote channel draft sills of asrailway car tothe inner faces of which are securedv front stop lugs 11 and rear-stoplugs A.12. A portion of a draw bar is indicated at 13, the same beingoperatively associated with the shock absorbing mechanism proper by 'ahooded cast yoke 14 and coupler'key 15. The yoke andshock absorbingmechanism are adapted to be supported in operative position byadetachable saddle plate 16. v l v The improved shock absorbing mechanismproper, as shown, comprises, broadly, l'a combined friction shell andVspring cage casting A; a main sprino' resistance B; a pair a combinedvfollower preliminary spring F; anda retainer bolt G.

The casting A, at its outer or forward end, is provided with vtop andbottom horizontally extending walls 17-17 and vertical side walls 18-18thereby defining what may be termed a rectangular friction shell orbarrel having longitudinally extending interior fiat friction surfaces19-19 onv the inner sides of the sidewalls 18-18. Rearwardly of theshell'- proper just described, the side walls of the casting A areoffset inwardly asindicated at 20-20 to define the spring cageV properfor v centering the main.

spring B. At its rear end the casting A is formed with an integraltransverse vertical wall 21 adapted to act as the "rear follower of themechanismf Suitable strengthening ribs are employed to brace the wallsof the casting A. v

' The friction shoes C are two in number and of like construction. Eachis formed on its lll outer side with a longitudinally extending fiatfriction surface 22 slidable upon the cor responding shell frictionsurface 19. 0n its inner side, each shoe C is formed with a relativelywide wedge face 23 'extending .at a relatively blu-nt langle withrespect to the axis of the mechanism. Above and below the wedge face 23each shoe C is formed with Kother wedge faces 24--211 which 'extend at arelative-ly keen angle with respect to tlre axis of the mechanism., saidwedge faces 24 being on wings '25-25 integral with the inain lpart ofthe shoe. @naccount of the wedge formation of each shoe C there isprovided a transverse shoulder 26 near the inner -end thereof andagainst which the forward end of lthe main spring B isadapted to bear.The lopposite end of the spring B presses against the rear portion ofthe casting A.

.The iblunt wedge element E is formed on the sides thereof with wedgefaces 12S-123 cooperable with the wedge faces 23 of the shoes andextending at the same 'angle as the latter. At its outer end, the wedgeelef ment E is formed with a transversely extending surface 27 and aAcup-shaped 'or cylindrical .recess 28 .in ,axial alinement with the thecenter-line off the `mechanism and in which -the preliminary spring visadapted to belseated.

The combined wedge follower D is formed to'fprovide a main frontfollower section 29 directly cooperable with the stop Vlugs 11. On litsinner sidev it yis provided with upper and flower inwardly `extendinghorizontally disposed flanges S-30, eachfof which is tapered inwardly soAas to provide wedge faces 1.24-124 on the 'edges thereof, said `wed-gefaces .124 -extending at the same tangle as 'the wedge lfaces 241ofytheshoes. Preferably the wedge follower l-D `is built upon its innerside'as indicated at 811, :between the "wings 30V-,#30: and 4ayrelatively shallow apocket .or recess 321isprovided in which is'seatedlthe forward end of the preliminary spring F.

The Iretainer bolt Gr is anchoredlat lits `rear end in a hollow bossformed integrally with the casting yA andat Iits forward'end in asuitable socket formed in wedge :follower D. Said-bolt extends axiallyofthe inain'spring B between Ythe shoes C, :through 'a suitable aperturein the wedge Velement E and through the vpreliminary spring 'E Thepreliminary `spring F is of yunusual constructionin-order to obtainexceptionally high Capacity with a short rstrokewithin a small space. Tothis end, the :preliminary spring -'F' preferably comprises .three likecoils 33e-33, each coil extendingfthrough an arc of substantially 360oand :having 'the ends of each coil squared off as indicated at 34 inFig. B. Each coil or single turn is made of relatively heavy wire or barmaterial, with a pitch somewhat less than the diameter of the bar sothat the squared ends of one coil will face and abut the squared endsAof adj acent .coils. vBy employing three independentcoilswhich 'are inparallel abutting relation as shown, l am enabled to obtain a springcapacity for the unit which is three times that ofthe capacityV of eachsingle coil 33. For a more complete descrip- `tion of the advantages andmanner of operation of such a spring, reference may be had to cospendingapplicati-.on 441,127 tiled January 31, 1921 for high capacity springs.At this point, it may Ibe added that itheicompression stroke 'of :mypreliminary spriin'g F bis)compara'tively short,slightly more than ahalf inch in actual practice, but this adoes not militate against thefunctions of the preliminary spring since only 'a short compressionstroke is fdesirable for a preliminary VVVaction. 0n the contrary, highcapacity 4of a true spring nature is desirable for the zpreliminaryspring :and l believe l am .the first in the art to provide apreliminary spring having the; -high ccapacity referred to fand where:suchvspring is of :such compact form. In vnormal conditionof :thefparts, as shown in Eig. 1, there :is a space Vindicated:at285 betweenthe y.opposing portions yof the wedge follower :D and :the `wedgeelement E and also there is normally a space between "the keen Vwedge:faces 2li-and 124in order to provide for -the Operation now to begdescribed. The operation is as follows, 'as'sinning an inward Vor 'buingrinoafeanent of the idfraw bar. As the latter ymoves inwardly 'the wedgefollower D :is inwardly, simultafne-V ously and :uniformlymovedstherewith. .'lnitially, -sufcient resistance will be Vafforded thewedge'element E on account ofthe main spring reacting .through the shoesC te :prevent any .appreciable .ino-vement of vthe blunt wed-ge elementE. Consequently, any minor shocks or-short movementsl of the `wedgeYfollower D, which constitute the greater .portion of the shocksoccurring in actual service, will be Vabsorbed by the preliminary springF without involying:any appreciable wear on any Gif-ftheifrictionelements. This isof .extreme importance `inasnnich as itprolongs the life of the mechanismand also affords a lrelatively high`spring resistance for even the preliminaryforf'small shock-s.`-Heretofore, where a springlliavingvazcompression stroke equal to the.full `movement of Vthe draw bar 'has been femployed Ftozabsor'b thepreliminary movements, .fthe .capacity for lresistance afforded 'by the:spring during the lirst lhalfV inch or 'so 'of fitscolnpression fliasbeen an extremely `small percentage of fthe full capacity of irthespring as'will Abe un! derstood by fthose skilled in Athe art byvconsidering the ordinary compression diagram of aspring.

y If the shock on the draw bar in the buihng movement is suflicientlygreat so that it is not entirely absorbed by the preliminary spring Fwithout actuation of the friction shoes, the continued inward movementof the wedge follower D will gradually start up the blunt wedge elementE and compel the latter and the shoe C totravel inwardly. As thewedgeelement E andshoes C travel inwardly of the shell, the resistancelobviously gradually increases until the preliminary spring F will bestill further compressed and the wedge follower D allowed to advancerelatively to the wedge element E. Its action continues until the wedgefaces 124 of the Wedge follower D comes into contact with the wedgefaces 24 of the shoes which is the condition illustrated in Fig. 4. Theparts will be so designed that, at this point in the stroke ofthemechanism, there will be some clearance left between the wedge followerD and the element'E as indicated at 135 in Fig. 4. When the condition isrigid as shown in F ig. 4,V the wedge action on the shoes becomes thatof. a keen Vwedge thereby automatically increasing the outward pressureon the shoes and the frictional resistance of the mechanism. Theclearance 135 is left for the reason that, as the keen wedge membersadvance or tendto advance longitudinally of the shoes C, there will be aslight relative movement between the same and the blunt wedge elementr Edue to the slower inward movement ofthe latter, the parts being soproportioned that there will not be actual contact between. the followerD and the element E. For the remainder of the compression stroke afterthe parts have reached the condition shown in Fig. 4, the act-ion issubstantially that of the keen wedges 124 acting on the shoes C.

In release, uponvdiscontinuance ofthe actuating force there isianimmediate expansion of the high capacity preliminary spring F whichdisengages the keen wedge faces 124 fromthe wedge faces 24-thussubstantially instantaneously.releasing the shoes of the keen wedgepressure and automatically substituting the blunt .wedge .faces 123. Thecollapse or release of the shoes may be-easily effected' under theexpansion of the main spring B Vreacting through the shoes and by theslight contraction of the friction shell which, as will be understood bythose skilled in the art,vwill haye' been 'expanded slightly during thecompression stroke.

From the preceding description, it will be seen that I have designed almechanism' which not only provides an, initially high ciapacitypreliminary spring action,`but also a mechanism wherein a changeVisfautomatically and-graduallyeifected from a preliminary springresistance to a blunt wedge action and then from the latter to a keenwedge action and wherein the wedging' system is self-releasing. v

I have herein shownl and described what I nowA consider they preferredmanner lof carrying out the invention, but the same is by way ofdescription konly and -not by way of limitation. All changes andmodifications are contemplated that come within the scope of therclaimslappended hereto. Y f

I claim l l. In a lfriction lshock absorbing mechanism, the kcombinationwith a friction shell and a main spring resistance; of friction. shoescooperable with said shell and having Wedge faces extending at differentangles with respect to the line of movement-of thel shoes;l and amultiple part self-releasing wedge system, the elements of which havewedge faces cooperable with said different t angled Wedge faces oftheshoes, and means for normally maintaining a spaced relation between thewedge faces on one of said elements and the co-acting wedge faces ofsaid shoes. i f

2. In a friction shock absorbing mechanism, the combinationy with afriction shell and `a main spring resistance; of friction shoescooperable with said shell and havingv wedge faces extending atdifferent angles with respect to the line of movement of the slices; amultiple' lpart self-releasing wedge system, the elements of which havewedge faces cooperable with said different angled wedge faces oftheshoes, said multiple part wedge system including two-separate wedgeelements; and means for normally maintaining a spaced relation between.the -wedge faces of one of said elements and the 'coacting Wedge facesof said shoes.

3. In a friction shock absorbing mechanism, vthe combinationy with afriction shell and a main spring resistance; of friction shoescooperable with said shell and having wedge faces extending at differentangles with respect to 'the line ofl movement of the shoes; and amultiple part self-releasing vwedge system, the elements of which havewedge faces cooperable with said differentangled wedge faces of theshoes, said dierent angled lwedge faces beingl so disposed that a yplaneextending transversely to the line of movement of the shoes willintersect all of said wedge faces.

4. Iny a lfriction shock absorbing mecha'- nism, the combination with afriction shell and a main spring resistance ,of friction shoescooperable -with said shell and 'having ywedge faces extending atdifferent angles withv resp'ect'to the line ofl movement of the shoes;and a multiple part vself-releasing wedge system, the elements of whichhave wedge faces cooperable with said different. angled wedgeA facesofthe shoes, said multiple part wedge system including. two sepail Orate wedge .elements and a spring interposed therebetween, .all .of.said Adifferent `ang-led wedge faces being so located that a planeextending transverse to the line of movement of said shoes willintersect all .of said `wedge faces. i

A5. In a friction shock absorbing naechanism, vthe combi-nation with 4afriction shell and a main spring resistance; of friction shoescooperable with said shell, each shoe having a wedge face extending at arelatively 1blunt .angle with respect l.to the axis of the mechanism and.a wedge face extending at `a relatively iacute `angle with respect t0:the .axis of the mechanism; a multiple part wedge cooperable with saidshoes, said )multiple part Wedge including, two. .separate wedgeelements, .one of lsaid wedge .elements having wedge faces eooperablewith said acute Vwedge faces of `the-.shoes and the :other elementhaving wedge faces cooperahle with said blunt wedge faces of the shoes;:and ineans for :normally maintaining a .spaced relation between saidacute angle wedge faces of one of said shoes and the wedge faces .of theelement .co-.acting therewith.

16. In a friction Ashock absorbing mechanism, Ithe combination with afriction `:shell and a .main spring resistance; .of friction shoeszcoozperable with said shell fand having wedge faces extending atdifferent .angles with respect to the .-axis of .the mechanism;

Aand a multiple part wedge having wedge faces cooperable with said wedgelfaces of the shoes, said mutiple .part wedge including two .separatewedge elements and Va high ca pacit-y spring-interposed therebetween,said high capa-city spring comprising a plurality of separate coils inparallel abutting relation.

fr'. In a friction shock absorbing mechanism of -the characterdescribed, the combination with a friction shell; y'of a main spring.resist-ance; friction shoes -cooperable with said shell, each of vsaidshoes having `a relatively .blunt -angled wedge face and a relatively`keen .angled .wedge face; of I-a wedge .element `ihaving relatively'blunt angled wedge :fa-ces -coopera'ble with said blunt ywedge faces ofthe shoes; a second wedge'element Vhaving lrelatively 'keen angled wedgefaces adapted fto Lcooperate with said keen -angled wedge `faces of theshoes but normally out of contact ftherewith; `and spring means normallymaintaining said spaced relation between said sets .of ykeen angledwedge faces.

8. In a friction vshock absorbing mechanism :of .thecharacter described,y'the combination with a friction shell; -o'f -a .main

spring resistance.; friction shoes Acooperable with said shell, reach`of said shoesA having a'relativelyblunt angled .wedge-face and arelatively keen angled :wedge fface; of a Wedge 'element havingrelatively bluntang-led' nergens wedge facescooperable with sa-idblnntwedge faces of the shoes; a second wedge Aelement lnuvingrelatively keen angled. wedge. faces adapted to cooperate with `saidkeen angled wedge faces of the shoes but normally out of Vcontacttherewith; and a preliminary spring resistance interposed between saidheen angled v-.iedge element and the :blunt ang-led wedge element 9. Ina friction shoc absorbing mechanism, :the combination with a castinghaving a friction shell at ene end and a spring cage at the oppositeend; of a main spring resi-stance disposed within said cage; of aplurality of friction shoes cooperable with said. shell, each shoehaving a relatively :blunt angled wedge face and a relatively lkeenangled wedge face; of a wedge .element :having relatively .blunt .angledwedge faces .eooperable with and normal-ly in .contact with said bluntangled -wedofe vfaces of the shoes; asecond wedge element normallyseparated .from said first named `wedge element and lia-ving relativelyvheen angled wedge faces adapted to `cooperate with .the said :heenangled wedge :faces of the shoes :but normally separated therefrom; anda high capacity .preliminary spring interposed Abetween said wedgeelement, said high Vcapacity spring including a plurality .of separatecoils. in parallel abutting relation. Y

l0. ln a friction shock absorbing mechanism, the combination with Iacolumn-loadsustaining member :having friction :surfaces extending in thegeneral directionof length of said member; of friction shoes ycooperablewith the friction surfaces of said member and movable relativelylongitudinally thereof; -a main spring resistance operatively.interposed between lsaid member and shoes to yieldingly resist relativemovement therebetween; and a pressure-transmitting wedging dev-ice,including an .element having wedge faces, said wedge faces beinginitiallyV .ineffective to .exert wedge -aetion with respect to theshoes, ,but adapted to become effective after a predetermined relativemovement between the shoes and said member; and means yfor moving ftheshoes relative to said member yduring said initial relative movement.

ll. In a vfriction shock absorbing mechanism, the combination with a`column-loadsustaining member having friction surfaces extending in thegeneral direction of length of said member; of a friction systemco-operable with the Ifriction surfaces of said member and .movable l'asa unit lrelatively longitudinally thereof, -said system including aplurality off friction elements;a main spring resistancey operativelyvinterposed betweenlsaid -member and friction systemto yieldingly resistrelative movement therebetween; `and awedging device having wedge faces,said wedge faces-bei-ng-initially inef- In Witness that I claim theforegoing I have hereunto subscribed my name this 23rd -fectve to exertWedge action with respect to said friction elements but adapted tobecome eective after a predetermined relative initial movement betweensaid elements and member; and means for moving the elements relative vtosaid member during said initial relative movement. v

Witnesses CARRY GAILING, ANN BAKER.

